A winter storm that could bury parts of the U.S. Middle Atlantic region under 3 feet (90 cm) of snow slammed into Washington on Friday, threatening the nation's capital with record accumulations as it barreled up the East Coast.

The blizzard started to blanket the Washington area during the early afternoon. Six people had died in car crashes as a wintry mix spread across Arkansas, Tennessee and Kentucky.

The storm could dump 2 to 3 feet of snow on Baltimore and the capital and bring winds of 30 to 50 miles per hour (48 to 80 km per hour) before winding down on Saturday afternoon, according to the National Weather Service.

Philadelphia and New York were expected to get 12 to 18 inches (30 to 46 cm) of snow before the storm abates.

In Falls Church, Virginia, about 8 miles (13 km) west of the capital, a thick curtain of snow was already piling up on deserted streets on Friday evening, creating a peaceful tableau that disguised dangerous driving conditions.

"I want to be very clear with everybody. This is a major storm," Washington Mayor Muriel Bowser said as the city braced for what could turn out to be one of the worst storms in its history. "This has life-and-death implications and all the residents of the District of Columbia should treat it that way."

The Weather Channel said more than 85 million people in at least 20 states were covered by a winter weather warning, watch or advisory and residents up and down the East Coast scrambled to stock up on supplies.

Airlines canceled nearly 6,300 flights for Friday and Saturday, according to flight tracking website FlightAware.com. An additional 7,000 flights were delayed on Friday alone, reverberating to airports across the country.

Washington's snowfall could eclipse the "Snowmageddon" storm of 2010 that dropped 17.8 inches (45.2 cm), AccuWeather senior meteorologist Alex Sosnowski said. If forecasts prove accurate, the storm could rival the 1922 Knickerbocker storm, which dumped a record 28 inches (71 cm) on the city.